Make checkbuild depend on blueprint_tests

The Soong tests are being disabled by default, add them as a manual
dependency of checkbuild to esnure they still run in CI.

Bug: 269296618
Test: aninja -t path checkbuild out/host/linux-x86/bin/go/soong-java/test/test.passed
Change-Id: Ice9b5ecdef8455cd0b173edbac141861cffc28c1